Subject: Re: Possibly stupid GPL question
From: DJ Delorie <>
Date: Wed, 29 Sep 1999 17:19:25 -0400

> No, sorry . The NDA that you describe would be an unauthorized
> modification of my license terms. Concatenation of two agreements is
> possible _if_ the first agreement allows third parties to modify its
> terms with additional restrictions. The GPL _explicitly_prohibits_
> that.

But the GPL isn't the first agreement.  It's the second.  And the two
agreements aren't being concatenated, they're just coincidental.  If
the recipient is in a situation where they wouldn't be able to
redistribute the software anyway, the vendor won't violate the GPL by
giving them GPL'd software, because it isn't the vendor who imposed
the restrictions.  The restrictions were in place before the GPL was

If the vendor gave them software *with* a license that prohibited
redistribution, I'd agree with you.

Consider a case with three parties: The vendor requires that the
recipient have an NDA with a *third* party before they can give them
the software.  The vendor can (and usually must) choose to simply not
give them the software if they don't have an NDA.  No problem there,
as the GPL doesn't require redistribution.  If the recipient has an
NDA with the third party that precludes disclosure, and the vendor
gives them the software, who has violated what?  The vendor has
complied with the GPL - they have not restricted the right of the
recipient to redistribute.  If there are other reasons why the
recipient can't redistribute, that's not the vendor's problem.

Plus, if the NDA expires or is otherwise cancelled, the recipient is
left with the original GPL, and may then redistribute freely.  This is
not the case with a modified license.